Urethral Atresia Research Articles

Long-Term Outcomes in Children Treated by Prenatal Vesicoamniotic Shunting for Lower Urinary Tract Obstruction

Limited information is available about long-term outcomes in children treated prenatally for lower urinary tract obstruction. Our aim was to evaluate outcomes in children treated in utero with vesicoamniotic shunts. Clinical outcomes in 20 pregnancies with a singleton male fetus, oligo/anhydramnios, and lower urinary tract obstruction were studied using chart review and phone and written clinical questionnaire for parents, pediatricians, and urologists. Overall 1-year survival was 91%. Two neonatal deaths occurred from pulmonary hypoplasia. Mean gestational age at delivery was 34.6 weeks, mean days from shunting to delivery were 84.4, and mean birth weight was 2,574 g. Prenatal urinary prognosis was good in 13, borderline in 2, and poor in 3 of the survivors. Mean age at follow-up was 5.83 years. Posterior urethral valves were confirmed in 7 males, urethral atresia in 4, and prune belly syndrome in 7. Eight children had acceptable renal function, 4 had mild insufficiency, and 6 required dialysis and eventual renal transplant. Eleven children had normal bladder function with spontaneous voiding, 6 required catheterization, and 1 child still had a vesicostomy. Height and weight were below the 25th percentile in 9 children. Persistent respiratory problems were present in 8, musculoskeletal problems in 9, and frequent urinary tract infections were reported in 9. Health-related quality of life results in our group with lower urinary tract obstruction were similar to those in a healthy child population. Male children who underwent prenatal bladder shunting were neurodevelopmentally normal. Although one third of the surviving babies required dialysis and transplantation, the majority have acceptable renal and bladder function and report satisfactory quality of life. III.

Urinary ascites without hydronephrosis in a neonate with urethral atresia

Urethral atresia is a rare and usually fatal cause of prenatal bladder outlet obstruction. We present a case of urethral atresia with urinary ascites to highlight the difficulties in making the diagnosis in the absence of hydronephrosis. We also discuss possible reasons why this patient maintained normal renal and pulmonary function.

Correlation between ultrasound and anatomical findings in fetuses with lower urinary tract obstruction in the first half of pregnancy

The prognosis of fetal lower urinary tract obstruction (LUTO) depends upon renal function and also upon the underlying etiology. Precise identification of the latter remains a challenge antenatally. Our objective was to examine the underlying pathology in male fetuses with sonographic evidence of severe and isolated LUTO. Detailed postmortem examination was carried out after termination of pregnancy in 24 male fetuses presenting before 25 weeks of gestation with ultrasound evidence of isolated severe LUTO. All fetuses had megacystis and hyperechogenic kidneys. There was anhydramnios/oligohydramnios and pelvicalyceal dilatation in 20 and 15 cases, respectively. Posterior urethral valves (PUV) were suspected antenatally in 20 cases and urethral atresia was not suspected antenatally. However, postmortem examination of the urethra demonstrated atresia in six cases, severe stenosis in eight cases, PUV in nine cases and an apparently normal urethra in one case. Renal dysplasia was found in all cases but one. Urethral atresia was the most common urethral anomaly at 12-17 weeks. Hydronephrosis was more frequent in cases with PUV (8/9) and urethral stenosis (6/8) than with urethral atresia (0/6). In LUTO presenting in the first and second trimester, hyperechogenic kidneys were predictive of renal dysplasia in 95% of cases. The association of a sagittal diameter of the bladder of at least 40 mm with hydronephrosis before 28 weeks was predictive of PUV with a positive (PPV) and negative (NPV) predictive value of 44.4% and 66.6%, respectively. Absence of hydronephrosis and a sagittal diameter of the bladder of less than 40 mm were predictive of urethral atresia or stenosis with a PPV and NPV of 100% and 47.6%, respectively. The absence of hydronephrosis was predictive of urethral atresia with a PPV and NPV of 66.6% and 100%, respectively. LUTO in a male fetus presenting with megacystis in the first or second trimester of pregnancy is as likely to reflect urethral atresia or stenosis as it is PUV. The size of the bladder and the presence of hydronephrosis should be considered in order to improve prenatal diagnosis and counseling.

SQUAMOUS CELL PERITONITIS ASSOCIATED WITH HYDROMETROCOLPOS IN A MULTIMALFORMED NEWBORN

We present the case of a 1 day-old newborn with extensive squamous cell peritonitis resulting from vaginal atresia with hydrometrocolpos and squamous cell reflux through the genital system, a combination rarely recognized in the literature. Delivery was preceded by ultrasound diagnosis of oligohydramnios and “large bladder,” the latter representing the dilated proximal vagina. Additional findings included paraesophageal hiatus hernia containing squames, urethral atresia, absence of vulva, lung hypoplasia, mild hypoplasia of the corpus callosum, and short umbilical cord with single umbilical artery (SUA). The possible relationship of the SUA with the constellation of infradiaphragmatic malformations is discussed.

Spontaneous resolution of prenatal megalourethra

Urethral obstruction in the fetus is rare. Whereas proximal obstruction most often is caused by posterior urethral valves, causes of distal obstruction are less well recognized and can include urethral atresia, urethral webs, and anterior urethral valves. These latter abnormalities can lead to urinary retention, incontinence, enuresis, spontaneous bladder rupture, and megacystis. The authors present 3 fetuses (gestational age range, 18 to 20 weeks) in whom distal urethral obstruction was suspected by prenatal ultrasonography in the absence of a demonstrable lesion. All 3 experienced spontaneous resolution of the presumed obstruction. On follow-up, all are alive and well with no adverse genitourinary tract sequelae. No postpartum intervention was required.

P14.82: Does the obstructive level make differences in their outcomes? A study for pregnancies with fetal GI tract obstruction

Objective: To examine the underlying pathology in male fetuses with sonographic evidence of severe and isolated LUTO. Methods: Detailed postmortem examination was carried out after termination of pregnancy in 24 male fetuses presenting before 25 weeks of gestation with ultrasound evidence of isolated severe low urinary tract obstruction. Results: Gender was male in all cases. There was megacystis and hyperechogenic kidneys in all cases. There was anhydramnios/oligohydramnios and pelvicalyceal dilatation in 20 and 15 cases respectively. Prenatal diagnosis of the underlying condition was erroneous in 2/3 of the cases. Urethral atresia was never suspected antenatally. Examination of the urethra demonstrated atresia in 6 cases, severe stenosis in 8 cases, posterior urethral valves in 9 cases and an apparently normal urethra in one. Renal dysplasia was found in all cases but one. Urethral atresia was the most common urethral anomaly at 12–17 weeks. Hydronephrosis was more frequent in cases with PUV (8/9) and urethral stenosis (6/8) than with urethral atresia (1/6). In LUTO presenting before 25 weeks hyperechogenic kidneys was predictive of renal dysplasia in 95% of the cases. The association of a bladder larger diameter of more than 40 mm and hydronephrosis in a male fetus before 25 weeks was predictive of PUV with a PPV and NPV of 44% and 100% respectively. Absence of hydronephrosis and a bladder larger diameter of less (or equal) than 40 mm were predictive of urethral atresia or stenosis with a PPV and NPV of 83% and 57% respectively. Conclusion: LUTO presenting with megacystis in a male fetus in the first and second trimester can correspond to urethral atresia or stenosis more often than posterior urethral valves. Since the formers carry a poor prognosis size of the bladder and the presence of hydronephrosis could be the most discriminant association to improve prenatal counselling.

Prune Belly Syndrome and Tracheo-esophageal Fistula in a Premature Neonate.

Prune Belly Syndrome, also known as Eagle-Barrett syndrome, is a well known triad of abdominal muscle deficiency or hypoplasia, urinary tract anomalies, and bilateral cryptorchidism. Tracheoesophageal fistula is a sporadically occurring defect estimated to occur in 1 out 4425 live births. Only one case of Prune Belly Syndrome, tracheo-esophageal fistula associated with VATER syndrome, and urethral atresia occurring in the same individual has been reported. We present a unique case involving a 33 week fetus with bladder distention and bilateral hydroureteronephrosis diagnosed in utero who postnatally was diagnosed with Prune Belly Syndrome, tracheo-esophageal fistula, and urethral atresia.

Fetal cystoscopy in the management of fetal obstructive uropathy: experience in a single European centre.

To audit diagnostic and therapeutic fetal cystoscopy for suspected posterior urethral valves (PUV). In 13 fetuses, (14-28 weeks) the bladder was entered with a 1.3 mm embryo-fetoscope and intravesical findings documented. In 10 fetuses, an attempt was made to treat the obstruction by saline hydro-ablation (n = 4) and/or guide-wire passage (n = 9). Renal function was assessed post-natally at 10 to 34 months. The bladder wall was visualised in 12/13 cases and the bladder neck in 11; in 10 cases the upper urethra was entered, and the obstruction visualised in five. PUV were 'seen' in 4/9 confirmed cases, but also in one case of urethral atresia, while in two others the degree of resistance to guide-wire passage suggested atresia or prune belly. Therapeutic attempts were technically successful, at least initially, in 6/10 cases. Of the five cases with confirmed PUV and normal fetal urinary electrolytes, two have acceptable renal function at follow-up. Hydro-ablation in one case resulted in resolution of sonographic signs of obstruction, and ablated valves were confirmed post-natally. Semi-rigid fetal cystoscopy allows entry into the upper urethra in most obstructive uropathies, although bladder neck angulation precludes visualisation of the site of obstruction in the majority. Guide-wire passage or hydro-ablation may allow relatively atraumatic ablation of PUV in utero without the chronic bladder decompression associated with vesico-amniotic shunting. However, current technical limitations need to be overcome, possibly by the use of flexible or angled fetoscopes, before the role of cystoscopic treatment can be formally evaluated.

Continent catheterizable urinary conduit constructed from defunctionalized colon

The authors describe a technique for construction of a continent catheterizable stoma from distal defunctionalized colon in a patient with imperforate anus, urethral atresia, and sacral agenesis.

Reoperative Surgery for Anorectal Anomalies

Complications occur during the repair of anorectal malformations relatively frequently. Unfortunately, these complications are often preventable. Furthermore, the consequences of these complications are significant. Not only do patients experience unnecessary pain and suffering, but a secondary operation always renders less optimal functional results. A 20-year experience in the care of children with anorectal malformations was retrospectively analyzed. Patients who previously underwent surgical repair at other institutions, and subsequently required secondary surgery by the primary author were evaluated; 334 patients were identified. Reasons for reoperation included fecal incontinence in 77 patients; dehiscence and retraction in 96; recto-genito-urinary fistulae in 55; persistent urogenital sinus in 31 cloaca patients; acquired vaginal atresia in 21; acquired urethral atresia in 9; posterior urethral diverticulum in 20; and overflow pseudo incontinence in 25 patients. Except for fecal incontinence, all other complications are considered preventable. The source of the complications in almost all other settings are technical errors at the time of the primary repair. Recommendations are presented to help prevent these complications, and suggestions are made on how to treat them when they occur.

Ultrasonographic prediction of clinical pulmonary hypoplasia: measurement of the chest/trunk-length ratio in fetuses

Pulmonary hypoplasia is involved in patients with various surgical diseases. The aim of this study was to evaluate the clinical usefulness of measurement of the chest/trunk-length ratio (C/T) for predicting pulmonary hypoplasia in patients with congenital anomalies, with the exception of mass-like lesions in the thorax such as diaphragmatic hernia and cystic lung diseases. For measurement of C/T on fetal ultrasound, the sagittal section of the body trunk, including the spine, was analyzed. C/T was calculated as the chest length, defined from the top of the thorax to the top of the diaphragm, divided by the trunk length, defined from the top of the thorax to the bottom of the urinary bladder. From 1986 to 2000, measurements of C/T were undertaken in 49 healthy fetuses from 17 to 37 weeks of gestation and 98 fetuses with congenital anomalies, with the exception of intra-thoracic mass lesions, omphalocele, and fetal hydrops. Pulmonary hypoplasia was clinically assessed by the following criteria: (1) a lung-to-birth-weight ratio of 0.012 or less; (2) patients who required high-frequency oscillatory ventilation with mean airway pressure of 15 cmH(2)O or more with pure oxygen and/or who died presenting respiratory failure without evidences of meconium aspiration, congenital pneumonia, sepsis or hyaline membrane disease. For a predicting value for pulmonary hypoplasia to be obtained, sensitivity, specificity, positive predictive value and negative predictive value were quoted between C/T in patients with pulmonary hypoplasia and those without pulmonary hypoplasia. Healthy fetuses revealed the mean value as 0.38+/-0.03, with no significant change after 20 weeks of gestation. Pulmonary hypoplasia was assessed in 25 fetuses with urethral atresia and stenosis, renal agenesis, polycystic kidney, cloacal anomalies, diaphragmatic eventration, bronchopulmonary foregut malformation, chest deformity, meconium peritonitis and sacrococcygeal teratoma. As a predicting value for pulmonary hypoplasia, 0.32 or less of the maximum value of C/T indicated good accuracy, with a sensitivity of 92.0%, specificity of 95.9%, positive predictive value of 88.5% and negative predictive value of 97.2%. Ultrasonic measurement of C/T is useful in predicting postnatal respiratory conditions with regard to pulmonary hypoplasia.

P316: Postmortem findings in fetuses with severe lower urinary tract obstruction

To examine the underlying pathology in fetuses with sonographic evidence of severe urethral obstruction. Detailed postmortem examination was carried out after termination of pregnancy in 10 fetuses presenting before 22 weeks of gestation with ultrasound evidence of severe low urinary tract obstruction. There was megacystis in all cases, anhydramnios/oligohydramnios in nine cases, pelvicalyceal dilatation in 6 cases and hyperechogenic kidneys in 9 cases. Gender was male in all cases. Postmortem examination, including histological investigation of the urethra and kidneys, demonstrated renal dysplasia in all cases. Similarly, there was megacystis in all fetuses but the bladder wall was thick in nine and thin in one case. Examination of the urethra demonstrated atresia or severe stenosis in eight cases, posterior urethral valves in one case and an apparently normal urethra in one. The vast majority of fetuses presenting with sonographic features of severe low obstructive uropathy, the underlying cause is urethral atresia or severe stenosis. When these present in the first or early second trimester of pregnancy in a male fetus the prognosis is poor.

Early Second Trimester Intervention In A Surviving Infant With Postnatally Diagnosed Urethral Atresia

A 37-year-old woman (gravida IV, para II) was referred for screening fetal ultrasound at 14 weeks of gestation. The fetus was identified with a massively dilated bladder and normal amniotic fluid. At 15 weeks of gestation level III ultrasound demonstrated oligohydramnios, bilateral echogenic kidneys with hydronephrosis and the “keyhole” sign indicating profound bladder outlet obstruction (fig. 1). The remaining organ systems were unremarkable. Serial bladder electrolytes were obtained at 15, 16 and 17 weeks of gestation (see table). The parents decided to intervene despite a poor prognosis, and at 18 weeks of gestation a vesico-amniotic shunt was placed with immediate decompression of the bladder and restoration of amniotic fluid. At 30 weeks of gestation oligohydramnios was detected despite a decompressed urinary system, and elective cesarean section was performed at 34 weeks of betamethasone treatment. Peritoneal dialysis was instituted in the first week of life to manage renal insufficiency and oliguria. Since neonatal evaluation suggested bladder outlet obstruction, vesicostomy was performed. At age 14 months a 2 cm. proximal congenital urethral atretic segment was identified and serially dilated allowing closure of the vesicostomy (fig. 2). At age 30 months bilateral reimplantation with ureterocystoplasty was performed in an

Early Second Trimester Intervention In A Surviving Infant With Postnatally Diagnosed Urethral Atresia

Early Second Trimester Intervention In A Surviving Infant With Postnatally Diagnosed Urethral Atresia

Ultrasonographic findings of VATER association

Purpose: VATER association is a combination of congenital anomalies including vertebral defects (V), anal atresia (A), tracheoesophageal fistula (TE), esophageal atresia (E), and radial and renal anomalies (R). This report describes the prenatal progress of four such cases and the features of ultrasonographic findings.Methods: Case (1): the mother was referred at 12 weeks gestation because of a fetal abdominal cyst. Bilateral hydronephroses and an expansive bladder were detected by ultrasonography. At 36 weeks polyhydramnios appeared, and soon she delivered. V, A, TE, E and R were confirmed. Case (2): the mother was referred at 14 weeks because of a fetal abdominal cyst and oligohydramnios. Ultrasonography suggested megalocystis based on urethral atresia. An infant was delivered at 27 weeks and died right thereafter. Autopsy confirmed V, A, R, tracheal atresia, genital anomaly and megalocystis. Case (3): the mother was transported at 37 weeks because of fetal distress. Polyhydamnios had been suspected on a routine office visit. The infant was delivered by cesarean section. TE, E and limb defects were detected. Case (4): the mother was referred at 26 weeks because of anhydramnios and mediastinal shift. Ultrasonography and fetal MRI indicated renal agenesis and congenital diaphragmatic hernia. Autopsy on a stillborn infant revealed V, A, TE, E, R and diaphragmatic hernia.Results and conclusions: The features of ultrasonographic findings of VATER association were abnormality of urinary organs and amniotic fluid volume. However, in the cases with esophageal atresia, estimation of renal function was difficult.

OUTCOME ANALYSIS OF VESICOAMNIOTIC SHUNTING IN A COMPREHENSIVE POPULATION

Prenatal detection of obstructive uropathy is used widely and vesicoamniotic shunting is the accepted procedure in well-defined cases. We present outcomes of vesicoamniotic shunting in a consecutive series from a coordinated prenatal-postnatal treatment program. From 1989 to 1998 bladder obstruction was identified in 89 fetuses at a multidisciplinary prenatal high risk clinic. Prenatal intervention was considered in cases of bilateral hydronephrosis associated with evidence of bladder outlet obstruction and oligohydramnios. Indications for prenatal shunting were present in 12 patients (13%), and 9 underwent vesicoamniotic shunt insertion between weeks 20 and 28 of gestation. None of the prenatal procedures was associated with preterm labor, chorioamnionitis or urine chemistry values greater than cutoff threshold on bladder tap. Shunts were extruded from 2 fetuses, which required sequential insertion. After prenatal intervention 1 patient elected pregnancy termination and the others proceeded to term. Two neonates died at birth, and 6 survived. The underlying urological diagnosis was posterior urethral valves in 4 newborns, urethral atresia in 1, and prune belly variant and urethral atresia in 1. Of the patients 3 had relatively normal renal function, 2 had severe renal insufficiency and 1 had mild renal impairment. Five newborns are voiding freely and 1 underwent bladder reconstruction and is on intermittent catheterization. None of the patients had pulmonary problems at last followup. Although vesicoamniotic shunting is effective in reversing oligohydramnios, its ability to achieve sustainable good renal function in infancy is variable. No specific prenatal parameters were effective in predicting eventual good renal function. Pulmonary function cannot be assured with restoration of amniotic fluid.

Congenital Obstructive Uropathy: Its Origin and Contribution to End-Stage Renal Disease in Children

Most children with end-stage renal failure are born with abnormal kidneys, with fetal obstructive uropathy accounting for about half these cases. Posterior urethral valves (PUV) is overwhelmingly the most common, specific diagnosis, and is confined to boys. In general, the condition is sporadic, although familial cases have been reported, perhaps suggesting that genetic factors play a role in pathogenesis. PUV can present antenatally, detected on routine fetal ultrasonography, or postnatally, when it is associated with renal failure and bladder dysfunction. Advances in postnatal surgery and medical management have reduced the mortality in PUV, but it is uncertain whether antenatal diagnosis or treatment (eg, with vesicoamniotic shunts) improves long-term renal outcome. Other disorders associated with human fetal obstructive uropathy are urethral atresia, the prune belly syndrome, and multicystic dysplastic kidney. The nephropathy associated with fetal obstructive uropathy is renal dysplasia and comprises undifferentiated and metaplastic tissues. Several studies in animals and in humans suggest that fetal urine flow impairment causes deregulation of renal precursor cell turnover and expression of growth factor/survival and transcription factor genes. Furthermore, some of these morphologic and molecular changes can be ameliorated experimentally by fetal surgical decompression or administration of specific growth factors.

URETHRAL ATRESIA: LONG-TERM OUTCOME IN 6 CHILDREN WHO SURVIVED THE NEONATAL PERIOD

Urethral atresia is incompatible with life unless an alternative communication between the bladder and amniotic sac exists. Although antenatal intervention may improve perinatal mortality, clinical consequences remain. We outline the outcome after treatment of 6 patients born with urethral atresia. We reviewed the charts of 6 patients with urethral atresia treated at the Children's Hospital of Michigan between 1982 and 1999. Patient age ranged from 3 to 17 years (mean 9). All patients were males (46 XY) and presented at birth or in early infancy. Oligohydramnios was demonstrated in 4 of the 6 patients (67%). A vesico-amniotic shunt had been placed in 2 patients (at more than 30 weeks of gestation and in 1 at 17 weeks of gestation). The remaining 3 patients presented at birth with either a vesicocutaneous fistula or patent urachus. Bilateral or unilateral hydronephrosis was identified in 4 patients while 2 had severe renal dysplasia. Cystography identified moderate to high grade vesicoureteral reflux in all patients, and 5 (83%) had the prune belly syndrome. Mean serum creatinine at age 1 year was 1.3 mg/dl (range 0.5 to 2.1). Renal failure occurred in 5 patients (83%) before age 10 years and 4 of them have received a renal transplant. An average of 7.8 (range 9 to 14) urological procedures were performed on each patient. Progressive urethral dilation was not successful in the majority of our cases and ultimately 67% required some form of supravesical diversion. Our study demonstrates that urethral atresia is not necessarily fatal. Prenatal decompression allows survival and in some cases may even lead to normal bladder and renal function. A complicated clinical course requiring extensive reconstruction is to be expected.

Urethral atresia: long-term outcome in 6 children who survived the neonatal period.

Urethral atresia is incompatible with life unless an alternative communication between the bladder and amniotic sac exists. Although antenatal intervention may improve perinatal mortality, clinical consequences remain. We outline the outcome after treatment of 6 patients born with urethral atresia. We reviewed the charts of 6 patients with urethral atresia treated at the Children's Hospital of Michigan between 1982 and 1999. Patient age ranged from 3 to 17 years (mean 9). All patients were males (46 XY) and presented at birth or in early infancy. Oligohydramnios was demonstrated in 4 of the 6 patients (67%). A vesico-amniotic shunt had been placed in 2 patients (at more than 30 weeks of gestation and in 1 at 17 weeks of gestation). The remaining 3 patients presented at birth with either a vesicocutaneous fistula or patent urachus. Bilateral or unilateral hydronephrosis was identified in 4 patients while 2 had severe renal dysplasia. Cystography identified moderate to high grade vesicoureteral reflux in all patients, and 5 (83%) had the prune belly syndrome. Mean serum creatinine at age 1 year was 1.3 mg/dl (range 0.5 to 2.1). Renal failure occurred in 5 patients (83%) before age 10 years and 4 of them have received a renal transplant. An average of 7.8 (range 9 to 14) urological procedures were performed on each patient. Progressive urethral dilation was not successful in the majority of our cases and ultimately 67% required some form of supravesical diversion. Our study demonstrates that urethral atresia is not necessarily fatal. Prenatal decompression allows survival and in some cases may even lead to normal bladder and renal function. A complicated clinical course requiring extensive reconstruction is to be expected.

P46Differential diagnosis in fetal obstructive uropathy

Case reportA healthy 24‐year‐old secundigravida presented for a routine ultrasound examination at the 11th week of gestation. The scan showed a singleton pregnancy and the crown‐rump length (43.8 mm) was compatible with the gestation calculated from the last menstrual period. The foetal abdomen was distended by the presence of one only cyst (12 × 7.4 mm), compatible with distension of the bladder. There was no other evident abnormality. Amniotic fluid volume was normal for the first trimester despite total urethral obstruction. At 14 weeks still birth was found and the patient delivered three days later. Diagnosis was confirmed at autopsy. Post mortem examination confirmed a phenotypically normal male foetus consistent with 14 weeks gestation and weighing 70 gr. The abdomen was distended and the abdominal wall was thin. Internal examination confirmed the presence of an enlarged bladder. There was urethral atresia, with associated dilatation of the bladder but the ureter and kidneys were normal. Internal genitals were male with normal testicles and penis. Chromosome analysis was performed on foetal skin and karyotype was 46, XY.DiscussionCloacal dysgenesis sequence (CDS) is a rare cause of fetal obstructive uropathy (FOU). The prenatal differentition of CDS from other FOU is important because CDS is not amenable to in utero surgical intervention in the form of vescicoamniotic shounts. Differential diagnosis must be made with pathologies capable of determining cystic lesions localised in the inferior foetal abdomen, such as ovarian cysts, intestinal duplications, Hirschsprung disease, colic dilatation, imperforate hymen with hydrometracolps and megacystes–microcolon syndrome. Accurate prenatal diagnosis can be difficult and requires prolonged serial observations. The above‐mentioned pathologies have characteristics of relative ‘fixity’, while typical imaging of cloaca undegoes variations due to sequential filling in, or repletion, of the liquid contained in the urinary, genital and digestive components of the malformation. Moreover, intestinal obstruction is generally associated with polyhydramnios. In the first trimester diagnosis of cloaca anomalies are very difficult because there are no great changes in amniotic fluid volume and ascites rarely is present; serial examinations are required for enable definition of diagnosis.